1. Field of the Invention
The present invention relates to a method of applying a corrosion inhibitor to a parts mounted circuit board.
2. Description of the Prior Art
A corrosion inhibitor is finally applied to necessary parts on a printed circuit board on which parts are mounted. However, this application has been conventionally performed one by one by a manual operation. Further, since a mutual distance between the mounted parts is narrow, it is a significantly difficult operation to apply the corrosion inhibitor to only the necessary parts.
The present invention is made by taking the points mentioned above into consideration, and an object of the present invention is to provide a method of applying a corrosion inhibitor to a parts mounted circuit board in which an application of a corrosion inhibitor is performed by printing so as to apply the corrosion inhibitor to a large number of parts mounted circuit plate at one time, solve a troublesome in the case of manually applying to only the necessary parts and greatly improve an efficiency of a whole of the mounting process.
Therefore, in accordance with the present invention, there is provided a method of applying a corrosion inhibitor to a parts mounted circuit board, wherein a recess portion surroundings a part of a circuit board in which the parts are mounted is provided on a back surface, a mask having a through hole for applying the corrosion inhibitor formed in a mesh shape is used in a portion corresponding to that of parts on the circuit board to which the corrosion inhibitor is applied in the recess portion, and the corrosion inhibitor is applied by screen printing.
Further, as a means for forming the through hole for applying the corrosion inhibitor in a mesh shape, there is a method of punching a multiplicity of narrow holes by a suitable punching means such as an etching or the like and also a method of expanding a net on a through hole having a desired size.